Johnston said he had already been contemplating retirement before Gov. Sam Brownback signed legislation a week earlier designating the governor’s transportation secretary as the turnpike’s director of operations.

The new law takes effect in July. It doesn’t abolish the turnpike CEO’s job, but it puts the transportation secretary in charge of the daily administration of the 236-mile toll road.

Brownback contends the changes will create efficiencies. Critics see a power grab.